Generally, a medical solution container must meet a number of performance criteria, including flexibility, transparency, gas barrier property, drug compatibility, heat sterilization resistance, fall impact resistance, etc.
It is common used a flexible plastic bag with multiple chambers (two and more) divided by partition walls as the medical solution container. The medical solution container uses partition walls for various medical solutions kept in each chambers not to react with other medical solution kept in other chambers. And when the medical solution is in need to inject to a patient, the medical solution is mixed by pushing the multiple chambers for various medicals solution to be mixed. The mixed functional medical solutions are administered to a patent via spike port using a syringe with sanitary and safe.
In case of administering medical solutions by connecting a few or many medical solution bags or bottles, medical staff may mistake in injecting medical solution, but using the afore-mentioned medical solution having chambers divided by partition walls reduces the mistake by medical staff and gives various merits in keeping and handling
Various types of medical solution container are now available, for example, a double bag with an inner bag and outer bag, where the inner bag contains functional medical solutions and the outer bag covers the inner bag and blocks gas as like oxygen.
In this way, medical solution container having multiple chambers or single inner bag wrapped by outer bag have been studied from 10 years ago in Europe, and recently investigation for building up properties, i.e. fall impact resistance as well as gas or moisture barrier function are accelerated.
In general, the inner bag needs to have various properties such as oxygen and moisture barrier property, heat sterilization resistance, transparency, fall impact resistance, flexibility, etc.
Many patents, for example, Korean patent registration No. 10-0275989, Korean patent laid-open 2004-0086373, U.S. Pat. Nos. 6,017,598, 6,007,529, Japanese patent laid-open 1994-286087, and 2001-226499 disclose a medical solution container, which comprises a single layer type or multi layer type having α-olefin or styrene copolymer as an inner bag material. Due to its high constitution ratio of polyolefin, however, the inner bag material has weakness in sterilization at 121° C. and exhibits extreme variation of heat seal strength to temperature, that may make it difficult to maintain good quality, i.e. uniform strength, in easy peelable property.
The medical solution container needs to have good properties such as gas barrier property, fall impact strength, and, transparency, etc. Moreover, since the container is easily dropped, the inner bag must have sufficient properties, i.e. fall impact strength, flexibility, etc. In order to check impurities in functional medical solutions, the film with high transparency is preferably necessary. In addition to this, film for medical solution container guarantee transparency after sterilization of 121° C.
The container stores various functional medical solutions in separate chambers, and when the medical solutions in need to inject to a patient, the medical solutions are mixed by pushing the chambers for partition walls to be opened. Therefore, it is very important partition walls to have proper property. Concretely, the partition walls must keep various medical solutions tightly in state of sealing during keeping, transporting, handling, etc, but need to be open easily by pressure, for example pushing by hands, to mix various medical solutions. For the purpose of these, candidate materials for the container should have proper peel strength with non temperature sensitive on various parameters such as temperature, time and pressure in case of heat seal.
Such peelable heat seal makes adhesion strength increase depending on time or after heat sterilization, so that the partition walls of the container may not peel easily. In regard this, suitable materials, processing method and conditions must be settled. For example, the conditions of peelable heat seal of partition wall may be carried out at lower temperature and pressure, in short time, in comparison with the conditions of peelable heat seal of outer layer.
The present invention has improved easy peelability through adding styrene thermoplastic elastomer into an inner layer of multilayer film container; also the present invention has improved easy peelability with non temperature sensitive and safe quality after sterilization by adding the thermoplastic elastomer and polyethylene.